Traffic-related air pollution and supplemental folic acid intake in relation to DNA methylation in granulosa cells

Table 2 Associations between exposure to NO₂, supplemental folic acid intake, and age acceleration of granulosa cells

	Age adjusted		Age + surrogate variables adjusted		Fully adjusted*
	Mean difference	95% CI	Mean difference	95% CI	Mean difference	95% CI
High versus Low NO₂ exposure
Horvath clock	− 1.13	− 6.10, 3.83	0.53	− 1.32, 2.38	0.52	− 1.41, 2.45
GrimAge clock	− 1.94	− 7.55, 3.68	− 0.18	− 1.36, 1.01	− 0.21	− 1.42, 1.00
GC clock	− 0.94	− 2.78, 0.91	− 0.80	− 2.51, 0.92	− 0.57	− 2.36, 1.22
High versus low supplemental folic acid intake
Horvath clock	1.61	− 3.36, 6.57	1.40	− 0.43, 3.22	1.28	− 0.59, 3.15
GrimAge clock	− 1.99	− 7.62, 3.64	0.22	− 0.96, 1.41	0.34	− 0.85, 1.53
GC clock	0.18	− 1.69, 2.04	0.41	− 1.32, 2.13	0.40	− 1.36, 2.16

Age acceleration was calculated by regressing biological age (as predicted by various aging clocks) on chronological age and using the resulting residuals. Values that are positive indicate a faster aging process while negative values indicate a slower aging process. High NO₂ exposure was defined as > 34.1 ppb and low exposure was defined as < 11.7 ppb. High supplemental folic acid intake was defined as ≥ 800 µg/day and low intake was defined as < 400 µg/day
CI, confidence interval; GC, granulosa cell; NO₂, nitrogen dioxide
*Models were adjusted for age and the three surrogate variables as well as body mass index, education (≤ College degree, Graduate degree), and protocol (Antagonist/Flare, Luteal phase)

ISSN: 1868-7083